1. Field of the Invention
The present invention generally relates to a chip package structure, in particular, to a stacked-type chip package structure.
2. Description of Related Art
In this information explosion age, the market of multimedia applications rapidly expands. The integrated circuit (IC) package needs to be developed in accordance with the trends of digitalization, network localization, user friendliness and so on. In order to satisfy the aforementioned requirements, electronic devices must achieve the goals of high operating speed, multiple functions, higher integration, miniaturization, light weight, and low cost. Therefore, high-density packages, such as ball grid arrays (BGAs), chip scale packages (CSPs), flip chips, and stack-type multi-chip package modules are developed.
FIG. 1 is a schematic cross-sectional view of a conventional stacked-type chip package structure. Please refer to FIG. 1, the stacked-type chip package structure 100 mainly comprises a substrate 110, a first chip 120, a second chip 130, a spacer 140, a plurality of first bonding wires 150, a plurality of second bonding wires 160 and a molding compound 180. The substrate 110 has a first surface 110a and a second surface 110b. The first chip 120 is adhered to the first surface 110a of the substrate 110 through an adhesive layer 170, and is electrically connected to the substrate 110 through the first bonding wires 150. Similarly, the second chip 130 is disposed above the first chip 120, and is electrically connected to the substrate 110 through the second bonding wires 160.
The spacer 140 is disposed between the first chip 120 and the second chip 130 for fixing the second chip 130 on the first chip 110 and protecting the first bonding wire 150 from damage. The molding compound 180 is disposed on the substrate 110 and covers the first chip 110, the second chip 130, the first bonding wires 150 and the second bonding wires 160 for protecting them from damage and humidity. Furthermore, a plurality of solder balls 190 are disposed on the other side of the substrate 110, and therefore the stacked-type chip package structure 100 can be electrically connected to other electronic devices (not shown) via the solder balls 190.
The above-mentioned stacked-type chip package structure 100 utilizes the spacer 140 for placing the second chip 130 on the first chip 110 and protecting the first bonding wires 150 from damage. However, the height of the chip package structure is unable to be lower due to the usage of the spacer 140, and the volume of the chip package is unable to be compact, too. Therefore, the solution of how to make the stacked-type chip package structure more compact is highly desired in the technology of IC package.